# Guidance for Entering User Defined Adjustment Factor

The User Defined Adjustment Factor is a multiplicative bias parameter that can be used to adjust the estimated lifetime risk to account for additional sources of uncertainty or bias not presently included in the methodology for estimation of lifetime risk.

The default setting for the user-defined adjustment factor is a "Fixed Value" distribution type with a value of 1.0 entered in the Parameter 1 column. The default setting will have no affect on the risk results. For an adjustment with negligible uncertainty or to ignore uncertainty in this adjustment, select "Fixed Value" as the distribution type and enter a fixed value value in the Parameter 1 column.

Uncertainty in the adjustment factor may be described as a probability distribution. To enter an uncertain adjustment factor, select one of the distributions from the “Distribution Type” menu and enter the parameters required to define the selected distribution. The parameters required to define each distribution type are provided below.

In cases where fewer than 3 parameters are required, unnecessary parameters are inactive.

Distribution Type | Parameter 1 | Parameter 2 | Parameter 3 |
---|---|---|---|

Lognormal | median | geometric standard deviation | N/A |

Normal | mean | standard deviation | N/A |

Triangular or LogTriangular | minimum | mode | maximum |

Uniform or LogUniform | minimum | maximum | N/A |

Fixed Value | value | N/A | N/A |